Stuffing box for liquid pumps



ot.4,193s. l `W WEN'ZE. j Y 2,131,927

S-TUFFING BOX FOR LIQUID PUMPS Filed Nov. 16, 1935 v i INVENTOR mmezm Wmjez ATTO NEYS Patented oct-'4, 193s UNITED STATES PATENT OFFICE STUFFIN'G BOX LIQUID' Wilhelm Wenzel, Leuna, Germany, assigner to Farbenindustrie Aktiengesellschaft,

Frankfort-on-the-Main, Germany Application November 16, 1935, Serial No. 50,115

2 Claims.

quently cause trouble in operation by becoming leaky too rapidly. By reason of the fact that a stuiiing box cannot in practice be entirely-tight without causing the packing to become hot, a certain-amount of liquid alwaysl penetrates between the piston or shaft and the pack-4 ing material. This amount of liquid, hereinafter referred to as the trickle liquid, vaporizes or passes into the gaseous phase and is released from pressure whereby the necessary amount of heat/is withdrawn from the packing material and the metallic parts surrounding it. The packing material thereby loses its elastic properties. It becomes hard and within a short time the leakage of the packing increases to such an extent as to render a regulated further operation of the process impossible.

avoided by supplying the amount of heat necessary for the evaporation and releasing from pressure of the trickle liquid from outside the stuffing box to the place at which the evaporation or releasing from pressure of the trickle liquid takes place. The packing material thus loses no heat `by the vaporizatlon and releasing from pressure of the trickle liquid but onthe contrary 5 substantially maintains its original temperature and therefore ltselastic properties.

The supplying of the necessary amount of heat to the stuiiing box may be effected in different ways dependingon the shape and manner of operation of the machine as well as on the nature of the material to be conveyed. 'I'hus for example the material of the stuillng box may be provided with heating chambers or channels -through which the heating agent, as for example steam,4 hot wateror hot oil, is led. Similarly. one or more packing rings may be replaced by hollow rings through which the heating agent flows. `A1ternatively, the shaft or piston of the machine xmay be provided with borings and the heat supplied to the stuing box in this way. Electrical heating elements may also `be employed. In some cases it is advantageous to effect the supply of heat by the simultaneous employment of several of the said or similar means. Preferably the flow of heat from the stuiilng box to other parts of the pump is 4stopped by a suitable heat insulation of the housing of the stuiilng box.

I have now found that the said drawback isv Germany November v23, 1934 'The nature of this ,invention will be further described with reference to the accompanying drawing which shows diagrammatically by way of example means of supplying heat to stuffing boxes in accordance with this invention but the invention is notrestricted to the particular .arrangements shown.

Referring to Figure 1, the housing a of the s tufng box-is provided with a flat annular channel b. The heating .agent is supplied at c, flows through the annular space b and leaves the stuffing box housing a at d after it has given up the Whole or a part of its heat.

Referring to Figure 2J 'an H-shaped ring is interposed `between the packing and formsv two hollow spaces b and e. supplied at c, flows while giving up he'at through the outer hollow space b and leaves-at d. The,

ring. The heating agent is supplied and withdrawn parallel to the shaft through appropriate orifices in the packing.

15 The heating agent is Referring to Figure 3, the supply of heat is v effected through the shaft itself which for this purpose is provided with a corresponding boring through which the heating agent ows.

Referring to Figure 4, the supply of heat is I eifected through a heating coil embedded in the packing through which the heating agent is led.

What I claim is:-

1. A processof Apreventing the trickle liquid which iiows between the stufng box and the part of an apparatus operating on a readily vaporizabie liquid in contact vwith said stuffing box fromA impairing the packing of saidv box which`comprises supplying heat from a iiowing heating fluid to the zone of contact between said y stufling box and said apparatus part in an amount sufiicient to cause `vapcrization of said trickle liquid and confining said heating fluid so thatit does not mingle with said trickle liquid.

2. A process of preventing the trickle liquid which flows between the stuiiing box and the 

